Quaternary International 211 (2010) 123–143 Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint Investigating human and megafauna co-occurrence in Australian prehistory: Mode and causality in fossil accumulations at Cuddie Springs Melanie Fillios a, Judith Field a,b,*, Bethan Charles c a Australian Key Centre for Microscopy and Microanalysis, Electron Microscope Unit F09, The University of Sydney, NSW 2006 Australia b School of Philosophical and Historical Inquiry, The University of Sydney, NSW 2006, Australia c Department of Archaeology, The University of Sydney, NSW 2006 Australia article info abstract Article history: Human arrival in Sahul – Pleistocene Australia and New Guinea – has long been argued as the catalyst in Available online 3 May 2009 the decline and disappearance of a suite of extinct animals referred to as megafauna. The debate con- cerning causality in Sahul is highly polarised, with climate change often cited as the alternative explanatory model. On continental Australia, there are few datasets available with which to explore the likely processes leading to the extinction events. At the present time, there is one site in New Guinea (Nombe Rockshelter) and one on continental Australia (Cuddie Springs) where the coexistence and temporal overlap of humans and megafauna has been identified. The Cuddie Springs Pleistocene archaeological site in southeastern Australia contains an association of fossil extinct and extant fauna with an archaeological record through two sequential stratigraphic units dating from c. 36 to c. 30 ka ago. A taphonomic study of the fossil fauna has revealed an accumulation of bone in a primary depositional context, consistent with a waterhole death assemblage. Overall the faunal assemblage studied here (n: 8146; NISP: 1355) has yielded little direct evidence of carnivore damage or human activities. Post depositional factors such as physical destruction incurred by trampling, compaction of sediments, and/or the hydrological status of the lake at that time have played important roles. As the only known site on continental Australia where megafauna and humans co-occur, the Cuddie Springs faunal assemblage yields equivocal evidence for a significant human role in the accumulation of the fauna here. At the present time there is no evidential basis to the argument that humans had a primary role in the extinction of the Australian megafauna. The first colonisers are likely to have preyed upon those few species known to have persisted to this time, but their impact may have been restricted to the tail end of a process that had been underway for millennia prior to human arrival. Ó 2009 Elsevier Ltd and INQUA. All rights reserved. 1. Introduction Australian continent, the impact of colonising humans on habitat and fauna is much less clear (see Wroe and Field, 2006). First, The arrival of humans into new environments is often linked identifying the exact timing of colonization by humans has been with distinct and irreversible changes in habitat and faunal pop- problematic due to methodological issues with dating techniques, ulations. One of the best cited examples is New Zealand and the taphonomy and interpretation of stratigraphy (see O’Connell and subsequent extinction of the Moa and other bird species (Anderson, Allen, 2004, 2007); and second, the currently available chronolo- 2003). However, the events that have been well documented on gies for megafauna are few and provide no clear indication of islands are not always mirrored on continents, though the two are timing or direction in the extinction process (Field et al., 2008). The often treated as one (see Wroe et al., 2002, 2004a). On the nearby result of these two separate dilemmas is that almost any cause can be invoked for the Late Pleistocene faunal extinctions, and the two primary candidates – humans and climate change – are mostly presented as opposing positions rather than two elements of * Corresponding author: Australian Key Centre for Microscopy and Microanalysis, a complex puzzle (see Horton, 1984; Flannery, 1990; Wroe et al., Electron Microscope Unit F09, The University of Sydney, NSW 2006 Australia. Tel.: 2004a; Johnson, 2006; Koch and Barnosky, 2006; Wroe and Field, þ1 612 9351 7412; fax: þ1 612 9351 7862. E-mail addresses: m.fi[email protected] (M. Fillios), j.fi[email protected] (J. Field), 2006; Prideaux et al., 2007; Turney et al., 2008). As a debate [email protected] (B. Charles). continues over primary causes, empirical evidence implicating 1040-6182/$ – see front matter Ó 2009 Elsevier Ltd and INQUA. All rights reserved. doi:10.1016/j.quaint.2009.04.003 124 M. Fillios et al. / Quaternary International 211 (2010) 123–143 people in the extinction of the megafauna is yet to be revealed. Brook et al., 2006; Gillespie and Brooks, 2006). In each case the Recent claims of a human mediated extinction process in Tasmania association of megafauna and humans is proposed to be the result (Turney et al., 2008) are unsupported and no evidence of of disturbance: the megafauna bones have been ‘reworked’ into the a temporal overlap of humans with megafauna has yet been found more recent levels, and/or the artefacts have been introduced into (R. Cosgrove personal communication). Furthermore, full consid- the deeper megafauna bearing deposits from overlying disturbed eration of the potential for humans to effect a mass extinction is horizons. Initially, the megafaunal bones were argued to be a lag rarely given; though modeling studies have attempted to predict deposit (Roberts et al., 2001b). Gillespie and Brooks (2006) have this potential (e.g. Brook and Bowman, 2004), they are usually declared that the megafaunal bones are in fact ‘bed-load’ derived based on the rather poor datasets currently available and unproven from a palaeo-channel which can be seen in aerial photographs. assumptions about human behaviour (see Field et al., 2008). Roberts et al. (2001b) argued that the original (and older) sedi- Further advances in understanding the extinction problem in Sahul ments were removed by wind or water. Subsequently, 36 ka year are constrained by the sparse nature of the fossil record (Wroe and old sediments, charcoal and stones accumulated around the bones. Field, 2006). While megafauna in Australia are widely known from If the bones were bed-load or a lag deposit then they should exhibit pit traps in caves (e.g. Reed and Bourne, 2000; Prideaux et al., signs of significant weathering and abrasion. Skeletal elements 2007), it seems likely that any records of megafauna co-occurrence with thin cortical bone such as vertebrae would be severely with people will be located near or in watering points on the degraded, the processes either missing or damaged. If they are bed- landscape (e.g. the sites of Lancefield Swamp, Lime Springs and load there would be no coherent association of bones and fluvial Cuddie Springs), where large animals will more often be encoun- sorting would be evident in directionality and skeletal part repre- tered and taken (O’Connell, 2000). sentation (after Voorhies, 1969). Assuming that 36 ka bones would also accumulate with the archaeology, then the 36 ka faunal 1.1. Megafauna and Archaeology assemblages from this horizon (SU6A and SU6B) would exhibit markedly different preservation to the lag assemblage, and overall Sahul (Pleistocene Australia–New Guinea) has yielded only two there would be a great variation in Rare Earth Element signatures sites where the questions of human and megafauna coexistence can consistent with this scenario (see Trueman et al., 2005). be explored: Nombe Rockshelter, a limestone shelter in the New Other researchers have proposed a mechanism by which the Guinea Highlands; and Cuddie Springs, an ephemeral lake in semi- stones were moved downwards from a pavement (SU5) which seals arid southeastern Australia (Field et al., 2008). If humans have had the more recent (European) deposits from the underlying Pleisto- a profound impact on the Australian Pleistocene fauna, then this cene megafauna bearing sediments (Gillespie and David, 2001; should be apparent at one or both sites where an association and David, 2002; Brook et al., 2006). This thin capping (c. 5 cm thick and temporal overlap of humans and megafauna are found. At Cuddie c. 1 m subsurface) was interpreted by the site investigators and Springs, the association occurs over at least two stratigraphic geomorphologists as a deflation pavement, comprised predomi- horizons and is coincident with a palaeoenvironmental record of nantly of flaked stone artefacts, which formed over an extended vegetation and lake hydrology spanning this period (Field and time period of c. 10,000 years (Field and Dodson, 1999; Field et al., Dodson, 1999; Field et al., 2001, 2002, 2008; Field, 2004, 2006). 2002, 2001). In contrast, David and others believe it was laid down Cuddie Springs is part of a dreaming track across central by farmers 60 or so years ago, to stop cows sinking in the mud northern New South Wales. A long known Aboriginal Dreamtime around a central well. It is argued that ‘local farmers’ raided other story about Mullyan the eagle-hawk relates the formation of the (as yet unidentified) local archaeological sites for ‘gravel-sized fossil deposits (Anderson and Fletcher, 1934). While the presence of stones’ which they brought in with horse drawn drays (Gillespie giant, extinct marsupials and flightless birds at Cuddie Springs has and Brooks, 2006). Any stones found in association with the been established for over a century, it was only in the early 1990s megafauna were pushed down by cow hooves when the sediments that an archaeological record was identified (Wilkinson, 1885; were wet. If the faunal assemblages are in situ and have not moved Anderson and Fletcher, 1934; Dodson et al., 1993; Furby et al., 1993). from elsewhere, then the archaeological stone assemblages intro- The evidence recovered therein helped to reignite the debate on the duced by the trampling of cows, would effectively be homogenous timing and cause of the Late Pleistocene faunal extinctions in through the whole of SU6.